Needle for delivery of dermal filler threads

ABSTRACT

Provided herewith is a needle for delivering dermal filler thread to a wrinkle in a patient. The needle can also be used to deliver the thread to a patient for the purposes of facial contouring. The needle comprises a coupler for attaching the thread to the needle and also a trocar to ease delivery through the skin.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.15/267,060, filed Sep. 15, 2016, which is a continuation of U.S. patentapplication Ser. No. 14/126,741, filed Dec. 16, 2013, which is aNational Stage Entry of PCT/US2012/42800, filed on Jun. 15, 2012, whichclaims the benefit under 35 U.S.C 119(e) to U.S. Provisional ApplicationSer. No. 61/498,364, filed Jun. 17, 2011, the entirety of which isincorporated herein by reference.

FIELD

This relates generally to delivery devices for dermal filler threads.The delivery device is useful for delivering a thread to a patient, forexample a facial wrinkle.

STATE OF THE ART

Dermal fillers have become prevalent in the field of aestheticintervention. When dermal fillers were first studied in the 1980's,animal derived collagen fillers were most popular. However, due to skinallergies, dermal fillers of hyaluronic acid have become preferred overcollagen due to fewer allergic reactions and better pliability. To date,dermal fillers approved for use in human patients to fill wrinklesconsist mainly of gel compositions. Examples of these gel compositionsinclude those made with hyaluronic acid, such as Restylane® andJuvederm®.

As gels can be difficult to deliver in a targeted manner to wrinkles inthe face, more structural forms, such as threads, are currently beinginvestigated. As described in WO 2010/028025, to fill a wrinkle with athread, the thread is attached to a needle at its proximal end. Thedistal end of the needle is then inserted through the skin surface ofthe subject into the dermis (or other layer) adjacent to or within thewrinkle. The needle then traverses the dermis of the subject. The needleexits the skin and by pulling the needle distally, the thread isdeposited into the wrinkle. Heretofore, an effective means of attachingthe thread to the needle for depositing a thread into a wrinkle has notbeen described.

SUMMARY

Provided is a device for delivering a dermal filler thread to a patient.

In one embodiment is provided a needle for delivering a dermal fillercomprising a tubular body having a proximal portion and a distalportion, a coupler in its proximal portion for mechanically attaching adermal filler to the needle, and a trocar in its distal portion.

In another embodiment is provided a kit comprising at least one needlefor delivering a dermal filler comprising a tubular body having aproximal portion and a distal portion, a coupler in its proximal portionfor mechanically attaching a dermal filler to the needle, and a trocarin its distal portion. The needle of the kit is coupled to a threadwhich is biocompatible and compressible. In one embodiment, the threadis comprised of hyaluronic acid, salt, hydrate or solvate thereofoptionally wherein at least a portion of the hyaluronic acid, salt,hydrate or solvate thereof is cross-linked.

Further embodiments are described throughout.

DETAILED DESCRIPTION OF THE DRAWINGS

The following detailed description is best understood when read inconjunction with the drawings. It should be noted that the variousfeatures of the drawings may not be to-scale. On the contrary,dimensions of certain features are arbitrarily expanded or reduced forclarity. Included in the drawings are the following figures:

FIG. 1 is a schematic illustration of one embodiment of a needle havinga coupler comprising struts.

FIG. 2 is a schematic illustration of a needle having a couplercomprising a funnel.

FIG. 3 is an exploded view of 1A from FIG. 1. The close-up shows acoupler having cleats in the shape of tabs.

FIG. 4 is an alternative exploded view of 1A from FIG. 1. The close-upshows a coupler having cleats in the shape of teeth.

FIG. 5 is a side view of a coupler having three pairs of struts wherethe pairs are symmetrically placed along the longitudinal axis of theneedle. This embodiment is sometimes referred to as having “mirroredstruts”.

FIG. 6 is a side view of a coupler having three pairs of struts wherethe pairs are staggered along the longitudinal axis of the needle.

FIG. 7 is a side view of a coupler having cleats in the shape of teeth.

FIG. 8 is a perspective view of a coupler having tabs and struts.

FIG. 9 is a perspective view of a coupler having slits and no struts.

FIG. 10 is a perspective view of a coupler having struts andteeth-shaped cleats.

FIG. 11 is a perspective view of a coupler having three slits withstaggered struts.

FIG. 12 is a side view of a coupler having v-shaped strut andteeth-shaped cleats.

FIG. 13 is a side view of a coupler having a u-shaped strut andteeth-shaped cleats.

FIG. 14 is a side view of a coupler having u-shaped struts andteeth-shaped cleats.

FIG. 15 is a perspective view of a trocar having three cutting edges.

FIG. 16 is a perspective view of a trocar having four cutting edges(with only two cutting edges showing).

FIG. 17 is a perspective view of a trocar have four cutting edges wherea pair of adjacent edges are substantially planar. The other pair ishidden.

FIG. 18 is a perspective view of a thread attached or coupled to anexemplary needle described herein.

FIG. 19 is a schematic illustration of one embodiment of a needle havinga hypotube coupler.

FIG. 20 is an exploded view of 19A from FIG. 19. The close-up shows acoupler having cleats in the shape of tabs.

FIG. 21 is a face view of a hypotube coupler.

FIG. 22 is a photograph and a schematic of the side view of an angledhypotube coupler attached to a needle.

FIG. 23 is a photograph and a schematic of the side view of a flushhypotube coupler attached to a needle.

FIG. 24 is a photograph and a schematic of the side view of a hypotubecoupler having eight crimp points.

FIG. 25 is a photograph and a schematic of the side view of a hypotubecoupler having four crimp points.

FIG. 26 is a photograph of the side view of a needle having a hypotubecoupler with four crimp points attached to a thread.

FIG. 27 is a schematic of a needle having a detachable coupler withthree threads of different diameters having a coupler attached.

FIG. 28A is a schematic of a needle having a detachable coupler insertedthrough the dermis.

FIG. 28B is a schematic of a needle having a detachable coupler insertedthrough the dermis with a thread attached.

FIG. 29A is a schematic of a straight sheath.

FIG. 29B is a schematic of a sheath with a pull tab.

FIG. 29C is a schematic of a sheath with a pull tab and an insertionpreventer.

FIG. 30A, FIG. 30B, and FIG. 30C are schematics of a sheath with a pulltab and an insertion preventer as it is inserted into and pushed throughthe dermis.

FIG. 31 is a schematic of a sheath, needle and thread further with aneedle grabber.

FIG. 32A and FIG. 32B are schematics of a self-buckling sheath.

FIG. 33 is a schematic of a self-buckling sheath after insertion of theneedle and thread into the dermis.

FIG. 34A and FIG. 34B are schematics of a self-buckling sheath afterinsertion of the needle and thread into the dermis.

FIG. 35A shows a sheathed needle and thread.

FIG. 35B shows a sheathed needle and thread inserted into puppet skin.

FIG. 35C shows a sheathed needle pulled through puppet skin, where thesheath is held at the insertion site, effectively removing sheath byentirely passive means.

FIG. 35D shows the sheath completely removed from the needle and thread.

DETAILED DESCRIPTION Device

Provided in FIG. 1 is one embodiment of a needle 10 having a distalportion or end 12, a proximal portion or end 14, and a tubular body 16.In some instances, the tubular body 16 may either have a lumen or besolid depending on the stiffness desired. In all instances, the tubularbody will have sufficient stiffness to be inserted into and throughdermis, epidermis, and/or subcutaneous tissue.

The proximal portion or end 14 comprises a coupler 18 as shown invarious embodiments in FIG. 1, FIG. 2, FIG. 3, FIG. 4, FIG. 5, FIG. 6,FIG. 7, FIG. 8, FIG. 9, and FIG. 11. As used herein, the terms “portion”and “end” are used interchangeably. The coupler 18 is a means formechanically attaching a thread to the needle 10 for delivery to anylayer of skin. The coupler at its proximal end 20 (as shown in thefigures just mentioned) has an inner diameter that is substantially thesame as the outer diameter of the thread that is being attached. In oneembodiment, the coupler 18 is continuous with the tubular body of theneedle 10, meaning that the distal end of the needle 10 is manipulated(e.g., laser cut or crimped) to serve as the coupler 18. In anotherembodiment, the coupler 18 is a separate piece from the needle 10 and isaffixed thereto by any number of means.

In some embodiments, the needle 10 further comprises a sheath (FIG. 29A,FIG. 29B, and FIG. 29C). The sheath fits over the coupler 18 once thethread 10 is attached to provide additional structural support to thecoupler 18. The sheath may be thin-walled heat shrink material, such aspolyethylene teraphthalate (PET) or polytetrafluroethylene (PTFE).

In one embodiment, the coupler 18 is designed such that it can beexpanded to a greater inner diameter and thus allow a portion of thethread to be placed into the coupler. The thread is then insertedthrough the length or a substantial portion of the length of thecoupler. Once the thread is placed into the coupler, the expandedcoupler is then crimped or closed to a diameter that fits the thread. Insome instances, it is an inner diameter more similar to its unexpandedinner diameter or even smaller than the unexpanded inner diameter of thecoupler 18. The coupler 18 is crimped to an outer diameter to allow forease of delivery through the skin but still allows the thread tomaintain its structural integrity. Once this crimping occurs, the threadis mechanically attached to the coupler and thus, the needle. In oneembodiment, the expansion is about 120% (i.e., from 0.010″ to 0.022″inner diameter (ID)) and crimping back down to 110-150% (0.011″-0.015″ID).

Due to the design of the coupler, the thread is not easily detached fromthe coupler/needle during delivery to aid in the accurate positioning ofthe thread.

To aid in the ability of the coupler 18 to expand its inner diameter toplace the thread, a variety of modifications may be made to the coupler.In one embodiment, one or more slits 22 are made along the longitudinalaxis of the coupler. These slits 22 can be made by cutting, lasercutting, chemical etching, or stamping and rolling the coupler. In someembodiments, the coupler will have two or three slits as shown in FIG.9. In one embodiment, each slit 22 is placed about equidistantly apart.Depending on whether the coupler 18 is the same or a different piece ofmaterial than the needle will determine how long the slit 22 or slits 22may be. If the coupler is the same piece of material as the needle, theslit(s) may run the entire length of the coupler. Further, the inneredges of the slits 22 may be smooth or serrated.

In addition to slits, the coupler may also comprise one or more struts24. The strut 24 is shown in FIG. 3 and FIG. 4. As shown in FIG. 12, thestrut 24 can be v-shaped 26 or as shown in FIG. 13 and FIG. 14, thestrut 28 can be u-shaped. Typically, the struts 24 are sized to maintainthe integrity of the metal employed. In some embodiments, the ratio ofthe wall thickness of the coupler 18 to the width of the strut 24 at itswidest part is about 1:1. The struts are similar to those used in stentdesign, however, in vascular stents, the struts allow a stent to becrimped down to a minimal diameter for ease of delivery through a smallcatheter and then expanded back to their original size. With the strutsdescribed herein, the struts allow the coupler to be expanded to receivea diameter thread that is larger than the unexpanded inner diameter.Once the thread is inserted, the struts allow the diameter to be crimpeddown to a small profile to be threaded through the skin.

In some embodiments, the slits 22 in the coupler comprise one strut 24but can comprise up to 6 or 8 struts. As shown in FIG. 5, the coupler 18can comprise two slits 18 that are cut along the same plane. In thosetwo slits, there are anywhere from one pair to four pair of struts. Whenthe struts are present in even numbers, additional hoop strength isprovided to the coupler. In the FIG. 5, there are 3 pairs of struts,although only three of the struts are visible in the side view. Theother three struts are in the same location in the other slit, mirroringthe slits in view. This is referred to as “mirrored struts.” In someembodiments the mirrored struts may be offset. Thus, the needle maycomprise one or more pairs of mirrored struts.

FIG. 6 provides a view of one embodiment of the coupler in its expandedposition. In this version of the coupler 18, there are two slits 22. Inthis embodiment, four struts 24 are shown. However, unlike in FIG. 5,the struts are staggered rather than mirrored. This staggered design maybe employed regardless of whether there are an even or an odd number ofstruts.

To further aid in the coupler's ability to engage the thread, the slits22 may also optionally comprise one or more cleats 30. The cleats 30 maybe selected from a variety of shapes, including tab-shaped, like seen inFIG. 3, FIG. 8, and FIG. 11, or teeth-shaped as seen in FIG. 4, FIG. 10,FIG. 12, FIG. 13, and FIG. 14. The cleats can be separately crimpedafter crimping of the coupler 18 to provide improved retention of thethread by the coupler 18.

In some embodiments, the coupler comprises both struts and cleats tomaximize retention of the thread. Various embodiments of a combinationof struts 22 and cleats 30 may be seen in FIG. 3, FIG. 4, FIG. 8, FIG.10, and FIG. 11.

The slits, struts and cleats may all be fashioned via laser cutting orother means.

In addition to the coupler providing the ability to be expanded, thecoupler may also serve as a funnel. This is shown in FIG. 2. The threadmay be extruded through the funnel and then it can dried or bonded tothe inner diameter of the funnel. The funnel then is attached to theproximal end of the needle. Alternatively, the thread could be insertedand adhered with a compatible adhesive into the back end of the funnel.Any number of adhesives may be employed such as cyanoacrylate or otherultraviolet curable adhesives.

As discussed above, in some embodiments, the coupler 18 is a separatehollow, substantially tubular piece which is attached to the proximalend of the needle 10 as seen in FIG. 19, FIG. 20, FIG. 22, and FIG. 23.This substantially tubular type of coupler is herein referred to as a“hypotube coupler”. As seen in FIG. 19, the proximal end of the needleis inserted at least partway, and in some embodiments about halfway,into one end of the hypotube coupler and is attached thereto by anynumber of means, including but not limited to, an adhesive, welding,crimping and/or heat shrink. In some embodiments, the hypotube coupleris laser welded to the proximal end of the needle. In one embodiment,the length of the hypotube coupler is about 0.2 inches (FIG. 20) and hasan inner diameter of about 0.02 inches (FIG. 21). As shown in FIG. 22and FIG. 23, the attachment profile 38 of the hypotube coupler can beangled or flush. In some embodiments, the attachment profile 38 of thehypotube coupler is angled, such that it provides gradual transitionwith the needle and therefore less drag through the tissue. In someembodiments, the attachment profile 38 of the hypotube coupler is flush.

Once attached to the needle, at least a portion of the hypotube couplerextends beyond the proximal end of the needle for housing the thread.The thread can then be inserted into the remaining portion of thehypotube coupler and affixed thereto. Once the thread is placed into thecoupler, the hypotube coupler is then crimped 42 around itscircumference to immobilize the thread (see FIG. 24 and FIG. 25). Insome instances, the hypotube coupler is crimped 42 at least four timesaround its circumference in one single plane, thus forming a “four-pointcrimp”, to immobilize the thread (see FIG. 25). Once this crimpingoccurs, the thread is mechanically attached to the hypotube coupler andthus, the needle. In some embodiments, a series of at least twofour-point crimps are used to secure the thread. FIG. 25 shows twofour-point crimps forming an “eight-point crimp”. The four-point crimpallows the use of a shorter hypotube coupler (e.g., 0.17 inches vs 0.25inches for the eight-point crimp) with less material. The eight-pointcrimp demonstrates a higher pull out force (i.e., the force required todislodge the thread from the hypotube coupler.) It is contemplated thatthe hypotube coupler displays a pull out force of greater than about0.400 lbf, or greater than 0.600 lbf, or greater than 0.800 lbf, or evengreater than 1.00 lbf. In some embodiments, the cumulative drag of theneedle 10 having a hypotube coupler 18 and thread 40 attached thereto(e.g., FIG. 26) is less than about 0.20 lbf-in, or less than about 0.10lbf-in, or less than about 0.075 lbf-in, or less than about 0.060lbf-in, or from about 0.1 to about 0.01, or from about 0.08 to about0.04, or from about 0.075 to about 0.045 lbf-in.

In certain embodiments, the design of the coupler is such that thethread is easily attached and/or detached from the coupler/needle duringdelivery to aid in the accurate positioning of the thread. Using such adetachable coupler allows the clinician to gauge effect by firstinserting the needle 10 into the dermis 50, selecting a thread 40 havingthe desired thickness and then attaching the thread to the coupler 18and pulling the thread through the dermis. See, for example, FIG. 27,FIG. 28A, and FIG. 28B.

In all embodiments of the coupler just described a variety of trocars 32may be employed. See, for example, FIG. 15, FIG. 16, and FIG. 17. In oneembodiment, the trocar has two, three (see FIG. 15), or four cuttingedges. In one embodiment, the trocar has four cutting edges, which issometimes referred to as a four-facet trocar (see FIG. 16 and FIG. 17).The four cutting edges can either be placed equidistant as seen in FIG.16 or a pair of adjacent cutting edges can be substantially planar asseen in FIG. 17. The other adjacent pair would then also besubstantially planar. When the cutting edges are substantially planar,the trocar's entry into the skin is less traumatic.

Typically, the needle 10, as well as the coupler 18 and trocar 34 aremade of stainless steel. The needle may also optionally include acoating. The coating may serve to enhance the lubricity of the needle,reduce friction, and/or may serve to cover any exposed laser cut edges.The coating may be either hydrophilic or hydrophobic. In someembodiments, the coating is applied by dipping or spraying the coatingonto the needle. In some embodiments, the coating is curable at roomtemperature and may be silicone based, such as a dispersion comprisingaminofunctional polydimethylsiloxane copolymer in a mixture of aliphaticand isopropanol solvents. In another embodiment, the coating is aheat-shrinkable material, such as PET or PTFE.

While the dimensions of any component just described, it is contemplatedthat a 27 gauge needle that is approximately 1″ to 4″ in length may beemployed. The inner diameter of the coupler is about 0.010″ and theexpanded inner diameter is about 0.021″. In some embodiments, thefollowing dimensions are also employed: 1) outer diameter of thread isfrom about 0.011″ to about 0.020″; 2) the length of coupler is about0.250″; 3) length of trocar is about 3.0″; 4) other suitable gaugeneedles include 24-30 gauge.

Threads

As shown in FIG. 18, a thread 40 is attached to a needle 10 at itsproximal end via the coupler 18. Although it is contemplated that anythread can be used, one embodiment is directed to the needle asdisclosed herein, with a biocompatible and optionally compressiblethread. Biocompatible refers to the fact that a substance will notproduce a toxic, injurious, or immunological response in living tissue.

For example, suitable biocompatible threads can comprise epoxies,polyesters, acrylics, nylons, silicones, polyanhydride, polyurethane,polycarbonate, poly(tetrafluoroethylene), polycaprolactone, polyethyleneoxide, polyethylene glycol, poly(vinyl chloride), polylactic acid,polyglycolic acid, polypropylene oxide, poly(akylene)glycol,polyoxyethylene, sebacic acid polymers, polyvinyl alcohol,2-hydroxyethyl methacrylate polymers, polymethyl methacrylate,1,3-bis(carboxyphenoxy)propane polymers, lipids, phosphatidylcholine,triglycerides, polyhydroxybutyrate, polyhydroxyvalerate, poly(ethyleneoxide), poly ortho esters, poly (amino acids), polycyanoacrylates,polyphophazenes, polysulfone, polyamine, poly (amido amines), fibrin,graphite, flexible fluoropolymer, isobutyl-based polymers, isopropylstyrene polymers, vinyl pyrrolidone polymers, cellulose acetatedibutyrate polymers, silicone rubber, hyaluronic acid, collagen,chondroitin sulfate, cyclodextrin, alginate, chitosan, carboxy methylchitosan, heparin, gellan gum, agarose, cellulose, poly(glycerol-sebacate) elastomer, poly(ethylene glycol)-sebacic acid,poly(sebacic acid-co-ricinoleic acid), guar gum, xanthan gum, andcombinations and/or derivatives thereof.

In certain embodiments, the threads comprise a thread of hyaluronic acidor salts, hydrates or solvates thereof or a thread of cross linkedhyaluronic acid or salts, hydrates or solvates thereof or a combinationthereof. Suitable hyaluronic acid threads are known in the art (see,e.g., WO/2010/028025, WO/2011/109130 and WO/2011/109129).

Accordingly, in one aspect, is provided a needle as disclosed hereinattached to a thread comprised of hyaluronic acid or salts, hydrates orsolvates thereof. In certain embodiments the thread is comprised ofcross-linked hyaluronic acid or salts, hydrates or solvates thereofcross linked with butanediol diglycidyl ether (BODE), divinyl sulfone(OVS) or 1-etllyl-3-(3-dimethylarninopropyl) carbodiirnide hydrochloride(EDC). Those of skill in the art will appreciate that many othercross-linking agents may be used to cross-link hyaluronic acid or salts,hydrates or solvates thereof. The above list of cross-linking agents isillustrative rather than comprehensive. In one embodiment the needle asdisclosed herein is attached to a thread comprised of cross-linkedhyaluronic acid or salts, hydrates or solvates thereof, wherein thehyaluronic acid has been cross linked with butanediol diglycidyl ether(BODE).

Methods of Delivering the Threads

The needles as disclosed herein, in combination with a biocompatiblethread, can be used in aesthetic applications (e.g., facial contouring,dermal fillers), surgery (e.g., sutures), drug delivery, and the like.

In one aspect, provided is a method of treating a wrinkle in a subjectin need thereof. A biocompatible thread is coupled to the proximalaspect of a needle as shown, for example, in FIG. 18. The distal end ofthe needle 10 or the trocar is then inserted through the skin surface ofthe subject into the dermis adjacent to or within the wrinkle and thedermis of the subject in the base of the wrinkle is traversed with theneedle. Once the needle exits the skin surface of the subject it ispulled distally until it is removed from the skin of the subject suchthat the thread is pulled into the location previously occupied by theneedle. The excess thread is then detached from the needle at the skinsurface of the subject. The detachment can be accomplished by cutting orbreaking the thread at or below the surface of the skin.

In another embodiment, provided is method of providing facial contouringin a subject in need thereof. In this embodiment, the needle attached toa thread is inserted into the dermis at or adjacent to the desiredtreatment location, e.g., the lips, the nasolabial fold, the teartrough, etc. The needle then applies the thread to the desired area,providing facial contouring. In one embodiment, a thread is applied tovarious planes of the dermal tissue. In one embodiment, several threadscan be placed generally parallel to each other and additional threadsplaces in a generally perpendicular direction with respect to the firstset of parallel threads thereby forming a mesh structure whose aggregateeffect is to contour a larger defect or more widespread defect such asthe tear trough or the infraorbital region of the eye.

Also contemplated are methods of using the needles of the inventionattached to biocompatible threads, hyaluronic acid threads for example,in surgery, ophthalmology, wound closure, drug delivery, and the like.

Further Embodiments

The clinical implementation of the needles attached to biocompatiblethreads, such as hyaluronic acid threads, as disclosed herein differsfrom how injectable dermal fillers are currently delivered. For typicalinjectable fillers, the prefilled syringe is acquired and a sterileneedle with a needle cover or cap is attached thereto. Once the needleis attached to the syringe, the needle cover or cap can be removedwithout the clinician coming in direct contact with the needle. With thepresent needle and thread, however, it may be the case that theclinician directly handles one or more of the components (i.e. theneedle and/or thread) which are being inserted and/or implanted into thepatient. Therefore, in some cases it may be desirable to implement acovering or sheath which can protect the entirety or a portion of theneedle and thread assembly from exposure and/or contact during theinsertion and implantation. FIG. 29A, FIG. 29B, and FIG. 29C showseveral sheath 42 constructs contemplated herein, each of which could beconstructed from material amenable to e-beam sterilization, such aspolyethylene terephthalate (PET), and may be colored to preventinadvertent implantation.

FIG. 29A shows a straight sheath 42 which covers the entire needle 10and thread 40. The straight sheath is of a diameter slightly larger thanthe needle and thread such that is readily removed by the clinician, butnot so large that is would be displaced during routine handling. FIG.29B shows a partial sheath 42 which houses the thread 40 withoutsubstantially housing the needle 10. In certain embodiments, the sheathcan be equipped with a pull tab at the proximal end (See, e.g., FIG.29B) which the clinician can use to pull off the sheath at the desiredtime. Such sheaths 42 could be removed either directly prior to orduring insertion of the needle 10 and thread 40.

In certain embodiments, the sheath 42 is designed with an expandeddistal edge to act as an insertion protector (FIG. 29C, FIG. 30A, FIG.30B, and FIG. 30C) by abutting the skin as the needle is inserted intothe patient while passively removing the sheath from the needle 10 andthread 40.

In certain embodiments, the sheath 42, needle 10 and thread 40 furthercomprise a needle grabber 52 which tightly and securely clamps theneedle 10 when grasped by the fingers of the clinician, and then allowsthe needle to slide freely when tension is released (FIG. 31).

In certain embodiments, the sheath 42 is a self-buckling sheath suchthat when the needle 10 is inserted into the dermis 50, the sheath 42buckles or cripples against the skin (FIG. 32A and FIG. 32B). As shownin FIG. 32B, as long as there is some un-buckled sheath distal to thegrab point 54 (i.e., between the skin and the point at which theclinician grasps the needle), the clinician can continue to insert theneedle 10 into the dermis. However, once the sheath is fully compresseddistal to the grab point 54, the sheath 42 must be pulled back. In someembodiments, once buckled and the tension at the grab point is removed,the sheath 42 remains buckled (FIG. 33). In another embodiment, oncebuckled and the tension at the grab point is removed, the sheath 42self-elongates (FIG. 34A and FIG. 34B).

1. (canceled)
 2. A needle for delivering a dermal filler, the needlecomprising: a dermal filler thread; a tubular body having a proximalbody portion, a distal body portion, and a longitudinal axis, wherein atleast a portion of the dermal filler thread extends through the tubularbody; and a sheath encasing the tubular body, the sheath having aproximal sheath portion and a distal sheath portion, the distal sheathportion having an expanded distal edge that has a cross-sectionalprofile that is expanded relative to a cross-sectional profile of theproximal sheath portion, the sheath being configured to permit aclinician to firmly grasp the tubular body for piercing a patient's skinwith the tubular body while abutting the expanded distal edge againstthe patient's skin thereby preventing the sheath from piercing thepatient's skin.
 3. The needle of claim 2, wherein the tubular body isconfigured to advance distally relative to the distal sheath portion. 4.The needle of claim 3, wherein the sheath is configured to buckle as thetubular body advances distally relative to the sheath.
 5. The needle ofclaim 2, wherein the sheath is configured to buckle against thepatient's skin as the tubular body is inserted into the patient.
 6. Theneedle of claim 5, wherein the sheath is configured to self-elongate. 7.The needle of claim 2, further comprising a needle clamp disposed aroundthe distal body portion of the tubular body, wherein the needle clamppermits sliding movement of the tubular body relative to the needleclamp in a released position and the needle clamp prevents slidingmovement of the tubular body relative to the needle clamp in a clampedposition.
 8. The needle of claim 2, wherein the dermal filler threadcomprises a hyaluronic acid, salt, hydrate or solvate thereof.
 9. Theneedle of claim 2, wherein the dermal filler thread comprises across-linked hyaluronic acid.
 10. A method for delivering a dermalfiller, the method comprising: providing a dermal filler thread within atubular body; at least partially encasing the tubular body with asheath, wherein the sheath comprises a proximal sheath portion and adistal sheath portion, the distal sheath portion having an expandeddistal edge that has a cross-sectional profile that is expanded relativeto a cross-sectional profile of the proximal sheath portion; abuttingthe expanded distal edge against a patient's skin thereby preventing thesheath from piercing the patient's skin; grasping the sheath and thetubular body; and piercing a patient's skin with the tubular body. 11.The method of claim 10, further comprising advancing the tubular bodydistally relative to the distal sheath portion.
 12. The method of claim11, further comprising removing the sheath from a distal portion of thetubular body as the tubular body is inserted into the patient's skin.13. The method of claim 11, further comprising buckling the sheath asthe tubular body advances distally relative to the sheath.
 14. Themethod of claim 10, further comprising buckling the sheath against thepatient's skin as the tubular body is inserted into the patient.
 15. Themethod of claim 14, further comprising: buckling the sheath to a grabpoint as the tubular body is inserted into the patient; and retractingthe sheath proximally relative to the tubular body.
 16. The method ofclaim 15, further comprising maintaining the sheath in a buckledconfiguration during retracting the sheath.
 17. The method of claim 15,further comprising expanding the sheath from a buckled configuration.18. The method of claim 10, further comprising clamping a distal portionof the tubular body.
 19. The method of claim 10, further comprisingadvancing the dermal filler thread through the tubular body.
 20. Themethod of claim 10, wherein the dermal filler thread comprises ahyaluronic acid, salt, hydrate or solvate thereof.
 21. The method ofclaim 10, wherein the dermal filler thread comprises a cross-linkedhyaluronic acid.